LOS ANGELES (Reuters) - The FBI plans to re-examine the beating death of a mentally ill California transient after a jury acquitted two ex-policemen of all charges in connection with the fatal confrontation, which touched off protests and political upheaval in the city of Fullerton.

Meanwhile, a lawyer for Jay Cicinelli, one of the two former officers at the center of the case, said his client would seek to be rehired by the Fullerton Police Department now that he had been cleared of involuntary manslaughter and use of excessive force charges in the 2011 death of 37-year-old Kelly Thomas.

Orange County prosecutors had accused the two men, who approached Thomas near a bus depot to question him about reports of vandalized cars, of turning a routine law enforcement encounter into an unnecessary and savage bludgeoning that cost the unarmed homeless man his life.

Defense lawyers won acquittals for Cicinelli and co-defendant Manuel Ramos in the case by arguing at trial that Thomas was dangerous and that the officers responded according to their training. They also said the transient suffered from a weak heart brought on by drug abuse.

“In 2011, the FBI opened an investigation to determine if Mr. Thomas’ civil rights were violated during an altercation with Fullerton police officers,” FBI spokeswoman Laura Eimiller said in a statement on Tuesday.

“With the conclusion of the state court trial, investigators will examine the evidence and testimony to determine if further investigation is warranted at the federal level,” Eimiller said.

Thomas’ brutal beating as he was subdued by six officers was caught on a surveillance camera at the bus station and led to angry street demonstrations in Fullerton, 30 miles southeast of Los Angeles, as well as the ouster of three city council members in a recall election.

On the videotape, Ramos is seen strapping latex gloves on his hands, balling them into fists in Thomas’s face and telling the drifter, whom he knew from previous encounters: “You see these fists? They are getting ready to f--- you up.”

By the end of the tape, Thomas can be heard screaming for help as officers swarm over him, delivering multiple blows and shocks with a stun gun. He is heard calling dozens of times for his father to help him, yelling: “Daddy, they’re killing me.”

Father Ron Thomas, speaking to reporters on Tuesday afternoon, called on the U.S. Department of Justice to prosecute Ramos and Cicinelli and said he would not abandon a civil lawsuit he filed against the officers, the Fullerton Police Department and the city.

“It’s very important that the federal government find reason to charge them and bring them into federal court,” said the elder Thomas, a former Orange County Sheriff’s deputy who had earlier described himself as “disgusted” by the verdicts.

“I look at this like a prize fight. It’s not over. We still have several rounds to go and we’ve been stopped so far, but I will not stop until we get justice for Kelly.”

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An attorney for Ron Thomas, Garo Mardirossian, said he had already subpoenaed all six Fullerton officers involved in the melee to give depositions in the case and would put them on the witness stand in the civil case.

Ramos, who was acquitted of second-degree murder and use of excessive force, and Cicinelli did not testify in their own defense during the criminal trial in Orange County Superior Court.

Defense attorney Zachery Lopes told Reuters in an interview that Cicinelli had contested his dismissal from the Fullerton Police Department in an administrative process that was put on hold during the criminal trial. Now that the trial is over, Lopes said, Cicinelli would resume that effort.

A spokesman for the Fullerton Police Department could not immediately be reached for comment.

The city of Fullerton has already agreed to pay $1 million to Thomas’s mother in a negotiated settlement of any claims she might have brought in her son’s death. The victim’s parents are divorced and litigating separately.

In 2012, Fullerton’s acting chief of police posthumously exonerated Thomas of any wrongdoing in connection with the confrontation, saying he was cleared of any suspicion that he provoked the violent struggle that led to his death.

(This version of the story corrects spelling of Zachery Lopes in paragraph 15)